What can I expect from a breast biopsy and getting my breast drained? Cyst on breast with nasty symptoms, worried it could e cancerous!

Low key. If this is a fluid filled cyst, it can be drained in the office after injecting xylocaine (lidocaine) and then putting a needle in the cyst to draw out (aspirate) the fluid. It takes just a couple minutes and will relieve the pain you are experiencing from the cyst. Good luck!
Hopefully... ...You will get peace of mind. Cancer at your age is uncommon, except for patients with strong family history but if your doc recommended a biopsy, you need to get it. Should be a simple, uncomplicated procedure. The worse part will probably be waiting for the results, but have faith and hang in there. I truly wish you the best.